Electromagnetic relay



July 12, 1932. I w. c. Rb E I 1,867,099

ELEC TROMAGNETI C RELAY Filed Sept. 11. 1926 INVENTOR [d 1 c. 19.

ATTORNEY Patented July 12, 1932 UNITED STATES PATENT OFFICE WILLIAM O. ROE, or rrr'rsmmon, PENNSYLVANIA, AssIGNOR T0 PBINTEL MANU- FACTURING CORPORATION, A CORPORATION OF NEW YORK ELECTBOMAGNETIO RELAY Application filed September 11, 1926. Serial No. 134,883.

1 My inventionrelates to electromagnetic reays. I

An object of my invention is to provide an electromagnetic relay which will be very sensitive and which will be capable of being adjusted 'to operate upon electrical current impulses of predetermined strength, quickly, and to operate-quickly upon current impulses of predetermined low value.

Another object of my invention is to provide a relay in which the disturbing influence of friction upon the moving part is substantially eliminated.

Another object of my invention is to provide an electrical relay of high sensitiveness, in which the electrical contacts are maintained in correct alignment at all times.

1 Another object of my invention is to provide a relay of the above character which may be readily precisely adjusted.

Other objects of my invention and the ini vention'itself will be more readily apparent by reference to the following description of an embodiment thereof and in which descrip tion reference will be had .to the accompanying drawing of said embodiment, forming a part of this specification.

Referring to the drawing, Fig. 1 is an inside elevational view of an embodiment of my invention Fig. 2 is an end elevational viewof the embodiment of Fig. 1; and r Fig. 3 is a plan view ofthe said embodi ment.

Referring now to all of the figures of drawing, in all of which like'parts are designated by like reference characters, at 1 and 2, I show two like electromagnets disposed parallel to each other, whose cores are joined at their rear ends by an electromagnetic yoke piece 3. The front ends of the cores project through openings 4 and 5 in the'front arm 6 of a substantially U-shaped frame having a rear arm 7 and'intermediate supporting portion 8, which supporting portion is preferably perfo'rated, as at 9 and 10, to permit securing screws to pass through the perforations tosecure the relay-to 'a mounting board or like support. A threaded lug 11 projects rearwardlyfrom the yoke 3, being rigidly 16, which project through the Openings 4 and 5 in the arm 6, as above set forth, whereby the 'normal air gap distancefrom the pole faces of the cores 15 and 16 to the armature 28 may.

be adjustably predetermined by rotating the adjusting nut 13. The electromagnetic windings on the cores 15 and 16 may be connected together, in series or parallel, according to the electrical conditions served by the relay,

in accordance with recognized practice.

Carried upon the end of the arm 6 but insulated therefrom, I provide a contact carrying bracket 18 carrying an electrical contact screw 19 and a stop screw 20 in such a manner that the electrical contact 21 of the screw 19 will be engaged by the armature carried con= tact 22 upon a forward or tracked position of the armature, and the contact element 23, which is of an insulating material, such as hard rubber, ivory, or like'material, is engaged by the rear face of the tongue 24 of the armature 28 upon a rearward or retracked movement of the armature or when the armature is in normal position, as illustrated. The contact portions of the screwsi19 and 20 can be advanced or withdrawn by turning the screws, which are screw threaded through the bracket 18, and their position may be set by tightening the clamping nuts carried on each screw. The bracket 18 is secured to the frame arm 6 by means of a screw- 25 and insulated therefrom and from the arm 6 by insulating washers 26, disposed on the two faces of the bracket, and an insulating bushing 27 surrounding the screw.

The armature comprises a transverse armature portion 28, and a supporting blade 29, having an upwardly extending tongue 24 and downwardly extending tongues 30. At 31, and preferably by the same rivets that secure the armature 17 to the blade 29, I secure a leaf spring 32, which is preferably bent at 33 and 34.- and perforated at 35, near its end, so that it may be advanced over the end of the threaded screw 36 secured to the arm 6 at 37 by screw threading it therein and advancing the clamping nut 38 to retain it .in position thereafter. An adjusting nut 39 is screw threaded on to the end of the screw 36, being brought into contact with the spring 32 to increase or decrease its pressure, which pressure is effective to press the tongues 30 on to the points of pins 40 which project within recesses 41 carr ed on the face of the armature tongues 30 next adjacent the support 6. The degree of angul'arity of the opposing walls of the pin 40 and recess 41 is such that the pin 40 has its tapered walls less inclined to the axis of the pin than are the walls of the recess 11. The angularity of the walls of the pin is more acute than the angularity of the walls of the recess, so that the armature being spring pressed by the spring 32 on to the points of the pins 40, which are disposed in transverse alignment relative to the longitudinal axis of the relay armature, may swivel on the pin points freely and without frictional contact of the pin with the tapered walls 0 the recess. Pressure of the spring 32 causes the points to find the deepest part of the recess, and the arrangement described of pin points spring pressed within spaced recesses insures that the alignment of the electrical contacts 21 and 22 will be preserved and that the armature may pivot on the pins with little or no resistance at the pins to its movement. The advancing of the adjusting nut 39 stressing the spring 32, by virtue of the placement of the pivot points intermediate the adjusting nut and the point of connection 31 of the spring with the armature, causes a retraction of the armature portions adjacent to the core 15 and contact 21, relative to such core and contact, and by additional pressure placed on the spring 32 by the nut 39, the retractive effort will be increased at the same time the pressure between the pin point and recess contacts is increased to hold the armature on its pivots.

Through this construction, with the pivot points in cupped depressions, the armature unit is held in an exact position relative to the contact screws and magnet poles, and practically all friction is eliminated. Though the armature is most free to oscillate upon the pivot points, absolutely no forward motion is lost in the movement of the. armature toward the magnets, all the motion imparted to the armature by the pull of the magnets being effective atthe contact points, and therefore the air gap can be made very small. The'pivots do not act as electrical conductors and are therefore free from any danger of being burnt and becoming rough. The

tension spring allows of a very fine adjustment of the armature reaction through the point tapered walls threaded stud and adjusting nut, the spring, nut and stud constituting a continuous conducting path from the frame to the armature unit. The suspension .of the armature is such that a correct relation is assured at all times to all of its other cooperative parts.

To disassemble the armature from the frame for cleaning the contacts. requires merely the removal of the adjusting nut 39, and the assembling of the unit is an easy task, since the respective parts are held together by the same units that function otherwise as the complete relay, there being required no additional flexible electrical conductor between the armature and frame since the spring 32 will effectively conduct current from the relay frame to the armature. The variable stresses exerted upon an armature in other constructions, by a coil of wire, are not present in this design.

Having thus described my invention in a specific embodiment, I am aware that numerous and extensive departures may be made from the invention herein illustrated and described but without departing from the spirit of my invention.

What I claim is:

1. In an electromagnetic relay, a core, an armature element, a winding adapted to energize the core and attractthe armature ele ment, a supporting element, said armature element making a two point contact with the supporting element, the contact at each point being had by a pointed pin of the one element projecting within a recess of the other, each recess having inclined walls substantially entirely closely surrounding the point of contact with the pin point, and spring means to maintain the points and recesses in pressed resilient engagement and.

the armature element in a retracted position, the inclination of the recessed walls directing the point therein to the portion of the recess of substantially greatest depth, being greater relative to the axes of the pins than element pro ecting within a recess of the oth-' er, each recess having inclined walls substantially entirely closely surrounding. the point of contact with the pin point, the inclination of the recessed walls directing the point therein to the portion of the recess of substantially greatest depth, being greater relative to the axes of the pins than the tapering walls of the pin point, and spring means continuously exerting an effort to press the pivoted portions of the armature forwardly I relative to the core and to maintain the points and recesses in pressed resilient engagement and to maintain the armature element m a retracted position.

3. In an electromagnetic rela a core, an armature element, .a winding a apted to energize the core and attract the armature element, a supporting element, said armature element making a two point contact with the supporting element, the contact at each point being had by a pointed pin of the one element projecting within a recess of the other, each recess having inclined wallsj'substantially entirely closely surrounding the point of contact with the pin point, the inclination of the recessed walls directing the point therein to the portion of the recess of substantially greatest depth, being greater rela tive to the axes of the pins than the tapering walls of the pin point, and spring means exertin an effort to press the pivoted portions 0 the armature forwardly. relative to the core and resiliently retracting the portion of the armature magnetically attracted by the core.

4. In an electromagnetic switch,a core, an armature element,a winding adapted to energize thecore and attract the armature element on a predetermined portion thereof, a supporting element, the said armature element being pivotally supported on the supporting element at twospaced points, the

pivot at each point comprising a pointed pin onone element projecting within a recess in the other element, aleaf-type spring secured to the armature element and having a portion disposed on the opposite side of the line of said pivot contacts from said attracted portion of the armature element and adapted to maintain the pivot points in resilient engagement and to maintain the armature element in a retracted position.

5. In a circuit controlling electromagnetic switch, an electromagnet having a core pole face and a frame, an armature formed to have three divergent arms, an end portion of one of the arms adapted to carrya circuit controlling contact, the endportions of the other arms making pivotal contact with the frame, the contacting ortions of said arms and frame comprising or eacharm a pointed pin projecting within a recess, each recess having inclined walls receding gradually from the point of contact with the pin point, to guide the pin point tothe portion of the re-' cess of substantlally greatest depth, the pin point having tapered walls spaced from the said receding recess walls when the point is positioned within the'recess, the armature eing reciprocable to two circuit controlling positions, a sprin 'to maintain the pivotal contact between t e arm portions and the frame, and to maintain the contact carrying arms in one circuit controllinghposition, said armature having a portion 'sposed intermediate the pivoted arms and the other arms netically attracted by said core pole face to move the armature to the other circuit controlling position.

6. In a circuit controlling electromagnetic switch, an electromagnet having a core pole face and a frame, an armature formed to have three divergent arms, an end portion of one of the arms adapted to carry a circuit controlling contact, the end portions of the other arms making pivotal contact with the frame, the contacting portions of said arms and frame com rising for each arm a pointed pin projecting within a recess, each recess having inclined walls receding gradually from the point of contact with the pin point, to guide the pin point to the portion of the recess of substantially greatest depth, the pin point having tapered walls spaced from the said receding recess walls when the point is. positioned within the recess the armature being reciprocable to two circuit controlling positions, a spring to maintain the pivotal contact between the arm portions and the frame, and to maintain the contact carrying arms in one circuit controlling position, said armature having a portion disposed intermediate the pivoted arms and the other arms closely disposed to and adapted to be magnetically attracted by said core pole face to move the armature to the other circuit controlling position, and an elongated spring longitudinally bendable joined to the armature at a portion on one side ofthe line 1 of said pivot and having al free end extending across the said line and an. vadjustment means supported by the frame to. adjustably press the end of the spring-towards the frame to apply resilient pressure to the said pivot and to resiliently retract the armature from said ole face.

7. n an electromagnetic switch, a core, an armature element, a winding adapted to energize the core and attract the armature element on a predetermined portion thereof, a supporting element, the said armature element being pivotally supported on the supporting element at two spaced points t e pivot at each point comprising a pointed pin on one element projecting within a recess in the other element, an elongated longitudinaL 1y bendable spring secured to the armature element and having a portion disposed on the opposite side of the line of said pivot contacts from said attracted portion of the armature element and adapted to maintain the pivot points in resilient engagement and to maintain the armature element in a retracted position.

In testimony whereof I hereunto aflix my signature this 22nd day of March, 1926.

; I wtLLmM o.- ROE. 

